title: Maternal and fetal characteristics associated with meconium-stained amniotic fluid.
abstract: OBJECTIVE
  To estimate the rates of meconium-stained amniotic fluid (AF) and adverse outcome in relation to gestational age and racial group, and to investigate the predictors of meconium-stained AF.
  
  
  METHODS
  We studied 499,096 singleton births weighing at least 500 g, at 24 or more weeks of gestation, from 1988 to 2000. The predictors of meconium-stained AF from 37 weeks of gestation onward were determined using multiple logistic regression.
  
  
  RESULTS
  The crude meconium-stained AF rates in preterm, term, and postterm births were 5.1% (95% confidence interval [CI] 4.9-5.4), 16.5% (95% CI 16.4-16.6), and 27.1% (95% CI 26.5-27.6), respectively; the rates in blacks, South Asians, and whites were 22.6% (95% CI 22.2-23.1), 16.8% (95% CI 16.5-17.1), and 15.7% (95% CI 15.6-15.8), respectively. Independent predictors of meconium-stained AF included being black (odds ratio [OR] 8.4, 95% CI 2.4-28.8), vaginal breech delivery (OR 4.7, 95% CI 4.2-5.3), being South Asian (OR 3.3, 95% CI 1.3-8.3), and being in an advancing week of gestation (OR 1.39, 95% CI 1.38-1.40). More blacks (17.9%, 95% CI 17.3-18.4) and South Asians (11.8%, 95% CI 11.5-12.1) with good outcome and no risk factors for fetal hypoxia had meconium-stained AF than did whites (11.2%, 95% CI 11.1-11.4). Using white neonates born at 40 weeks as reference, the absolute risk of adverse outcome at 41 and 42 weeks were 2% and 5% in whites, 3% and 7%, in South Asians, and 7% and 11% in blacks.
  
  
  CONCLUSIONS
  Meconium-stained AF rates are different among races and across gestational age, and overall risk of adverse outcomes in meconium stained AF is low.
  
  
  METHODS
  II.
authors.affiliation: From the Department of Obstetrics and Gynaecology, The Royal London Hospital, Barts and The London NHS Trust, London, United Kingdom; Epidemiology and Statistical Genetics, London School of Hygiene and Tropical Medicine, London, United Kingdom; Obstetrics and Gynecology, Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan; the Department of Obstetrics and Gynecology, Wayne State University, Hutzel Women's Hospital, Detroit, Michigan; and Imperial College Academic Department of Obstetrics and Gynaecology, Chelsea and Westminster Hospital, London, United Kingdom.
authors.forename: Imelda
authors.initials: I
authors.lastname: Balchin
authors.forename: John C
authors.initials: JC
authors.lastname: Whittaker
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Lamont
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Steer
mesh_terms: D000653:Amniotic Fluid; D015331:Cohort Studies; D005006:Ethnicity; D005260:Female; D005316:Fetal Distress / Q000175:diagnosis* / Q000208:ethnology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D008470:Meconium; D008471:Meconium Aspiration Syndrome / Q000208:ethnology / Q000209:etiology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000208:ethnology; D011256:Pregnancy Outcome; D011295:Prenatal Care; D012189:Retrospective Studies; D018570:Risk Assessment